At the local level of the National Weather Service are the Weather Forecast Offices (WFOs). Each of the 123 offices provide local expertise, forecasts, and warnings to their local aviation community. Offices are staffed 24 hours a day, seven days a week, with at least one forecaster dedicated to serving aviation interests on-shift at all times.

The primary aviation responsibility of the WFOs is to issue Terminal Aerodrome Forecasts (TAFs), a coded forecast consisting of the expected meteorological conditions significant to aviation interests within five statute miles of a given airport. Valid for a 24-hour period, TAFs are issued four times daily at 00Z, 06Z, 12Z, and 18Z, and updated as conditions warrant. TAFs include information about wind speed and direction, visibility, present weather, ceilings, and low-level wind shear. Additionally, WFOs issue an aviation discussion, highlighting forecast uncertainty and possible aviation hazards that may not be explicitly mentioned in the TAF, click here to learn more.

Routine Three Hour TAF Amendments

Background:

Based upon feedback from the Federal Aviation Administration Command Center, Weather Forecast Offices (WFOs) will provide routine TAF amendments for the 35 Operational Evolution Partnership (OEP) airports every three hours, at select airports amendments may be provided every two hours. This is to accommodate air traffic management coordination calls by providing the most up to date information, in addition, providing an updated forecast for the critical push times. Click here for more information from the Federal Aviation Administration (FAA) regarding OEP.

Method:

WFO forecasters should issue an amended TAF at 09z, 15z, and 21z daily. However, if the TAF has been amended within the previous hour (i.e. 08z and 14z), there is no need to issue another amendment. This is to encourage forecasters to update the TAF as needed, rather than wait for the routine issuance time. Routine amendments at other 3-hourly intervals (i.e. 03z) depend on the traffic demand at the specific airport. Forecasters should focus on the 0 to 3 hour time frame keeping in mind the critical "push" times. To see the airport arrival rates visit the Airport Arrival Demand Chart (AADC) website: AADC. Or contact the corresponding CWSU for information regarding the high traffic time window.